Trait for using mikey179/vfsStream with phpunit

VirtualFileSystem.php

<?php

namespace QWp6t\Tests;

/** composer require mikey179/vfsStream --dev */
use org\bovigo\vfs\vfsStream;

trait VirtualFileSystem
{
    protected $filesystem;

    public function setUp()
    {
        $this->filesystem = new class ($this->fixtures()) {
            /** @var \org\bovigo\vfs\vfsStreamDirectory */
            protected $stream;

            public function __construct($fixtures = [])
            {
                $this->stream = vfsStream::setup('__fixtures__', null, $fixtures);
            }

            public function __call($name, $arguments)
            {
                return $this->stream->{$name}(...$arguments);
            }

            public function __get($name)
            {
                return $this->stream->{$name};
            }

            public function __toString()
            {
                return $this->stream->url();
            }
        };
    }

    protected function write($file, $contents)
    {
        $file = str_replace('\\', '/', $file);
        $file = ltrim($file, '/');

        $file = "{$this->filesystem}/{$file}";

        file_put_contents($file, $contents);

        return $file;
    }

    protected function writeDump($file, $data)
    {
        $contents = var_export($data, true);
        return $this->write($file, $contents);
    }

    protected function fixtures()
    {
        $filesystem = [];

        foreach ($this->fixtures ?? [] as $file => $content) {
            $limbs = array_reverse(array_filter(explode('/', $file)));
            $filesystem = array_merge_recursive(array_reduce($limbs, function ($leaf, $limb) {
                return [$limb => $leaf];
            }, $content), $filesystem);
        }

        return $filesystem;
    }
}

Z1ExampleUsageTest.php

<?php

namespace QWp6t\Tests\Unit;

use PHPUnit\Framework\TestCase;
use QWp6t\Tests\VirtualFileSystem;

/**
 * NOTE the use of `$fixtures` property
 */

class Z1ExampleUsageTest extends TestCase
{
    use VirtualFileSystem;

    protected $fixtures = [
        'foo/bar.txt' => 'foobar',
        'biz/baz.log' => 'bizbaz',
    ];
    
    /** @test */
    public function it_should_read_contents_of_files()
    {
        $foobar = file_get_contents("{$this->filesystem}/foo/bar.txt");
        $bizbaz = file_get_contents("{$this->filesystem}/biz/baz.log");
        
        $this->assertEquals($foobar, 'foobar');
        $this->assertEquals($bizbaz, 'bizbaz');
    }
}

Z2ExampleUsageTest.php

<?php

namespace QWp6t\Tests\Unit;

use PHPUnit\Framework\TestCase;
use QWp6t\Tests\VirtualFileSystem;

/**
 * NOTE the use of `fixtures()` method
 */

class Z2ExampleUsageTest extends TestCase
{
    use VirtualFileSystem;

    /** @test */
    public function it_should_read_contents_of_files()
    {
        $foobar = file_get_contents("{$this->filesystem}/foo/bar.txt");
        $bizbaz = file_get_contents("{$this->filesystem}/biz/baz.log");
        
        $this->assertEquals($foobar, 'foobar');
        $this->assertEquals($bizbaz, 'bizbaz');
    }
    
    protected function fixtures()
    {
        $foobar = 'foobar';
        $bizbaz = 'bizbaz';
        
        return [
            ['foo' => ['bar' => $foobar]],
            ['biz' => ['baz' => $bizbaz]]
        ];
    }
}

Z3ExampleUsageTest.php

<?php

namespace QWp6t\Tests\Unit;

use PHPUnit\Framework\TestCase;
use QWp6t\Tests\VirtualFileSystem;

/**
 * NOTE the use of `$fixtures` property, `setUp()` override, and `write()` method
 */

class Z3ExampleUsageTest extends TestCase
{
    use VirtualFileSystem {
        setUp as vfsSetup;
    }
    
    protected $fixtures = [
        'foo/bar.txt' => 'foobar'
    ];
    
    public function setUp()
    {
        $this->vfsSetup();
        $bizbaz = 'bizbaz';
        $this->write('/biz/baz.log', $bizbaz);
    }

    /** @test */
    public function it_should_read_contents_of_files()
    {
        $foobar = file_get_contents("{$this->filesystem}/foo/bar.txt");
        $bizbaz = file_get_contents("{$this->filesystem}/biz/baz.log");
        
        $this->assertEquals($foobar, 'foobar');
        $this->assertEquals($bizbaz, 'bizbaz');
    }
}